Fluid bearing



'Filed July 8, 1950 NOV. 24, 1953 GERARD r AL 2,660,484

FLUID BEARING '5 Sheets-Sheet 1 I INVENTORS 0 ml y MrW Nov- 24, 1953' P. GERARD ET AL FLUID BEARING 5 Sheets-Sheet 5 Filed July 8, 1950 Fytjf.

INVENTORS Patented Nov. 24, 1953 FLUID BEARING Paul Gerard, Paris, and Henri Sranne, Villeurbanne, France, assignors to Gendron Freres, S. A., Villeurbanne, France, a company of France Application July 8, 1950, Serial No. 172,666

Claims priority, application France January 24, 1950 8 Claims.

In the U. S. patent application No. 699,051 of September 24, 1946 (abandoned following the filing on August 8, 1951, of continuation-impart application Serial No. 240,959), there has been described a bearing capable of holding in an integral floating state, a movable and more particularly a rotatable element journalled therein or thereon, even at rest, said floating state being ensured by a pressure fluid layer interposed bepressure of the feeding fluid is uniformly spread.

in the whole feeding zone through said system of grooves, the fluid thus forming a film capable of supporting the movable element without giving rise to sustained vibrations, even if said movable element is subjected to a considerable load. resulting in substantial specific pressures. It is to be understood that the deviceaccording to the invention may be used with any fluidtween at least a portion of the periphery of said 10 and, in particular, with liquids, within the scope element and the periphery of the bearing. of the invention.

According to the above-mentioned patent ap- Nevertheless, it is particularly proposed to use plication, it is possible to use as pressure fluid said device with compressed gases and, in parto form the above-mentioned layer, a liquid or a ticular, with compressed air, the advantages regas. A certain number of mbodiment h v 15 sulting from the novel arrangements of the feedbeen described in said application, but in these ing zones being in this case, par icul rly m rked embodiments, the pressure fluid feeding always A t er ject of the invention is to provide a took place through chambers between which are compressed gas bearing in particular, a comprovided substantially longitudinal grooves acting D d air bearing; c p s at least one com as fluid outlets. 20 pressed gas feeding zone having the shape of a We have found that the arrangements degroove system similar to the so-called oil groove scribed in the above-mentioned application were system separated by substantially longitudinal capable of giving excellent results when the feedchannels preferably having a a er Sectionalsing fluid was a liquid, i. e. a fluid havin a low suring, in conjunction with the first mentioned compressibility. We have found, in particular, grow/88,1116 eXhauSt 0f the a that even with relatively deep chambers receiv- The shape, arrangement, length and cross-secing a relatively considerable volume of fluid,'the tion of the grooves as well as the mode of feedrotatable element was supported without giving ing the groove syste W th the compressed a rise to sustained vibrations, even at veryhigh y e r d t en Wide l mits W thin the speeds and even when subjected to a considerable to scope of the invention- Thus, in particular, Said load.

We have noted, however, that with the abovementioned arrangements, appreciable sustained vibrations were to be observed when the feeding fluid was a compressed gas and, in particular, compressed air, i. e. a fluid having a high compressibility.

In particular, said vibrations become more and more prejudicial when the load acting upon the bearings is increased.

The main object of the invention is to provide a fluid bearing of the general type described in the above-mentioned application of Paul Gerard, i. e. of the type comprising feeding means to supply substantially longitudinal channels provided between the feeding zones, said bearing being characterized by the feature that the feeding zones, instead of being each constituted by one chamber, 1. e. by a capacity filled with a pressure fluid, are each constituted by a system of grooves of small cross-section, said systems being separated from each other by said substantially longitudinal outlet channels.

We have found that with the new and novel arrangements according to the invention, the

grooves may be fed at one point or at a plurality of points so as to ensure more perfectly the spreading of the compressed gas in each supporting zone of the bearing. According to one embodiment, the grooves may be arranged so as to form curvilinear rectangles limiting th feed zone, other grooves being preferably provided within said rectangles for feeding uniformly the whole zone limited by said rectangles. In particular, certain grooves may be arranged in a cross-like manner, so as to feed uniformly the active supporting zones.

According to another feature of the invention,

the bearing is so designed as to balance the re-.

sultant of the external forces acting upon the rotary element i. e. the shaft and, in particular,

gravity. According to this feature, the zones fed with a pressure fluid are so disposed that the symmetry plane of all supporting zones substantially-contains said resultant.

that against which the shaft tends to apply under the action of said resultant.

According to still another feature of the invention, the zones fed with the pressure fluid are arranged around the periphery of the bearing, said zones being of course separated by substantially longitudinal channels, said zones being fed in such a manner that the pressure existing in the zones resisting the resultant of the external forces, is preponderant. In particular, the abovementioned zones may be designed in a particular manner or may be so fed that the fluid pressure in said zones is higher than in any other fed zones.

According to another feature of the invention, the bearing zones are fed in the vicinity of their centre.

According to one embodiment, the grooves of the feeding system are fed from a source of con.- pressed gas through a suitable throttling.

According to another embodiment, said grooves are fed through diametrically opposed longitudinal grooves or channels. It is to be understood that the various feeding and outlet zones may be provided at will either on the outer surface of inner member, e. g., the shaft, or on the inner surface of the outer cylindrical member actin e. g., as a bearing surface and surrounding said shaft.

- The invention will be more easily understood with reference to the accompanying drawings showing, as a mere illustration, some embodiments of the invention.

In these drawings:

Figs. 1 and 2 are cross and axial sections, respectively, of a bearing of the type described in the above-mentioned patent application, i. e. of the type comprising chambers fed with a pressure fluid.

Fig. 3 is a diagram showing the curve of the radial displacement of a shaft journalled in a bearing of the type of Figs. 1 and 2, as a function of time, and the pressure curve in the same time, in the case when the fluid feeding said bearing is a liquid.

Fig. 4 is a similar diagram in the case when the fluid feeding the bearing is a gas.

Fig. 5 is a partial section of a fluid bearing in which the chambers fed with a pressure fluid are each substituted by a simple nozzle.

Fig. 6 is a pressure diagram in a bearing of the type shown in Fig. 5.

Fig. 7 is a partial section of a bearing according to the invention.

Fig, 8 is a partial development of the bearing shown in Fig. 7.

- Fig. 9 is a pressure diagram in a bearing according to the invention.

Figs. 10 to 13 show embodiments of a bearing according to the invention.

Figs. 14 and 15 are sectional views of a bearin according to the invention, Fig. 14 being a crosssection along axis XIV-XIV of Fig. 15, the lat ter being an axial section along axis XV-XV of Fig. 14.

Fig. 16 shows the development of bearing of Figs. 14 and 15.

Fig. 1'? is a half elevational view of a vertical bearing according to the invention and,

Figs. 18 and 19 show the bearing adapted to support a shaft which is carried around a portion only of its periphery instead of being completely surrounded by the bearing.

Referring first to Figs. 1 to 4, there is shown at l a bearing the inner periphery of which is provided with a certain number (five, in the example shown) of chambers 2 fed with a pressure fluid through inlets 3 and having longitudinal outlet channels 4. The pressure fluid is admitted into the hearing at 5 and penetrates rst into an annular chamber 5. A suitable cylindrical filter 'l' is provided in said annular chamber with which the above-mentioned inlets 3 communicate. The exhaust of the fluid takes place through the above-mentioned channels 5. which communicate with outlet ports 3 (Fig. 2).

In Fig. 2 is shown, as a mere illustration, a constructive embodiment in which the cylindrical sleeve which constitutes the body of the bearing proper is made in three pieces, via. a central ring 9 through which are drilled inlets 3, said rin; being machined to form feeding zones and outlet channels 3 and two collars liland I I forced on either side on said cylindrical ring 8 and soldered on the same as indicated at 52. Channels 4 provided in ring 9 extend across parts of collars it and H. Suitable shoulderings are provided as well between ring 5 and collars it, it as on the latter proper, said shoulderings determining the upper and lower zones of the annular chamber 5 within which is interposed filter soldered on the collars as indicated at it. It will be first assumed that the fluid fed into chambers 2 is a liquid.

In Fig. 3 is shown a curve at materializing as a function of time a given law of the shaft displacements in a well-defined transverse direction, e. g. under the action of the external forces. These displacements cause a variation of the resultant of the pressures exerted upon the shaft by the bearing. Curve 3) materializes the variations of said resultant as a function of time. It may be seen from curves at and p that there is no delay between the displacements of the shaft and the pressure variations resulting therefrom. If, however, the fluid feeding the bearing is a (having a high compressibility) the pressr' e curve pl will be delayed with respect to the placement curve dl (Fig. 4) and this time shift causes a sustained periodical motion of the shaft in the bearing even in the absence of any external force. This will be easily understood since, as the fluid feeding chambers 2 is compressible, the pressure increase due to the displacements will be necessarily delayed which will allow the shelf to move spontaneously with respect to the hearing, thus causing undesired vibrations.

A first solution would consist in suppressing completely chambers 2 and substituting therefore nozzles M as seen in Fig. 5. However, as shown in Fig. 6, the pressure curve would then present a peak along the axis of nozzle [4.

According to the invention, instead of suppressing chambers 2, the same are substituted by groove systems l5 (see Figs. '7, 8 and 9) With this arrangement, as shown in Fig. 9, the pressure curve offers a hat portion concentric to the bearing periphery, which gives the shaft a perfect stability. As mentioned above, the distribution of grooves E5 in each feeding zone may be varied between wide limits within the scope of the invention.

In Fig. 8, groove It: forms a rectangle completed by a mid-groove l5a interconnecting the longer sides of said rectangle, inlet M then opening in the centre of said mid-groove l5a.

Figs. 10 to 13 show the development of the surface of a fluid hearing.

In Fig. 10, grooves 15 are arranged in a crosslike manner along the diagonals of the feeding zones and comprise narrower portions at their ends.

In'Fig 1 1, grooves [5" are case arranged *a '--"cross-like manner but along the medians of saitl zones.

In Fig. 1 2,"grooves l5 "-area'fso 'arrangedfin a *cross-like manner'as in Fig. 10, but thecross 'thus "formed is completed-bytwo-grooves flib interconmeeting the ends o'f-thearms thereof.

:only essential condition being ato rprovide aasystem ofcgrooves having asmallxcross-section.

:In FigsHl-i to 16, is shown:as=an illustration a complete .embodiment of 'anxair hearing according to the invention.

In these figures. thereis shownat I the body of the bearing, at 2 the "peripherical feeding zone's C(flve, in the example shown) designated by -the iletters A,&B, C,.D,.El and at 3,-'ducts feeding zones 2 with a pressure fluid. The longitudinal outlet channels of the fluid are shown at 4, said channels being designated by letters a, b, c, d. e. 5 is as previously the inlet of the pressure fluid; 6 is the annual chamber and l the filter incorporated in said chamber. In this embodiment, there is provided, apart from the annular chamber 6, a series of annular grooves I, II, III, IV, groove II communicating directly with the above-mentioned annular chamber 6, and said grooves ensuring the communication between certain feeding zones and outlet channels through ducts 3, as described in detail hereafter. The shaft which is journalled in bearing I is shown at II.

In Fig. 16 is shown the development of the feeding zones A to E and that of the outlet channels a to e. The dotted line longitudinal strips numbered from I to IV show the above-mentioned annular grooves. The lower feeding zones A and B which have to balance the action of gravity should be fed at a higher pressure than the other zones. For this purpose, both zones A and B are connected in parallel with the annular groove II fed directly from chamber 6 and the other feeding zones are only fed downstream from said zones A and B and in series with the same. This series-feeding is obtained in the following manner: the fluid evacuated from the feeding zone A on either side thereof through channels 0 and d, is brought into feeding zones C and D, respective ly, through annular'grooves I and III, respectively. Similarly, the fluid evacuated from zone B through channels (1 and e is brought into zones D and E, respectively, through annular grooves III and IV, respectively.

The evacuation of the pressure fluid from zone C takes place through channel a; the evacuation of the fluid from zone E takes place through channel I); finally, the evacuation of the fluid from zone D takes place through channels a and r 1), simultaneously, the latter opening directly outside at 18 and I9, respectively. As shown in particular in Fig. 15, the shaft may be provided with a flange 23, so that the leakage fluid from the edges of the feeding zones forms between the shaft end and flange 23 a film preventing the flange from coming into direct contact with the bearing, the pressure in said annular zone automatically increasing as the clearance decreases.

In Fig. 17, is shown a pivot bearing I according to the invention, used as a thrust bearing adapted to bear a vertical rotor 11. In this extemple, *as shown on the lleft hand ihal'f :of the rfl-gurefithe 1? grooves F5 *are arranged around' the diagonals df th'e feeding zones, but on the outer surface of pivot l and hot gas 1 previously on "the "i'nne'r surface of the bearing. The incoming of the pressure fluid indicated by arrow F takes place through the face of pivot which is ho'l- 10w this e'rnbodiment and the evacuation of said fluid is effected as indicated by arrow F through each outlet-channel=4. Theaxial float- 'i-ng ofthe rotorzi-s en'sured by a pressure film' fii interposed between the -terminal face of pivot I and-the bottomof rotor l-l'. This film is :continuous'lysustained by 'theifluid flowing "through a throttling '22. In --"orde'r" to improve the ie'fii- 'ciency so'f the aXial sustentation device; it is possible to provide iin-lithe'r one of the plane isurifaces limiting film fl agroove system similar to '-thoseiislescrib'ed hereab'ove.

=-In'ithe "alternative embodiment shown inli'igs. IlBiarid ZlQ, shaft 11"!" :instead .of being surrounded '-;byi.bear.ing :l' 'n ests'nn ithei'samearound a portion conly-tof.its ,periphery. Grooves 1:5 are in this alternative embodiment arranged on the bearing (pillow-block) in a cross-like manner and along the diagonals of the feeding chambers; these grooves are fed through inlets 3 fed in turn by a duct 20 on which is screwed at 5' the pressure fluid inlet piping. A pressure fluid outlet channel is shown at 4".

What is claimed is:

1. A bearing structure adapted to support a rotor member by pressure of a low viscosity fluid continuously supplied thereto at a relatively high volumetric rate, said bearing structure comprising a rotor and a member con-centric to said rotor and interfitting therewith with a clearance therebetween, a plurality of circumferentially spaced and separated pressure zones between said concentric members, each said zone having formed in one of said members inlets for conducting said pressure fluid to one or more localized points therein, at least one groove extending along a surface of said zone from each said inlet and arranged to receive pressure fluid directly from said inlet and to distribute said fluid substantially uniformly throughout a major part of said zone, and axially extending outlet channels separating said pressure zones and adapted to receive and evacuate the pressure fluid from said zones at said relatively high rate, a major part of the area of each pressure zone being constituted by concentric surfaces of the movable members spaced no farther apart than the max-.

imum clearance between said members and said pressure zones constituting the major portion of the areas of the interfitting portions of said members whereby a substantially uniform high fluid pressure is maintained throughout the area of each of said zones to resist relative radial movement of said members.

2. A bearing structure according to claim 1 in which there are a plurality of grooves of relatively small cross-section radiatingin different directions from each inlet.

3. A bearing structure according to claim 2 which includes, in each pressure zone, another groove of relatively small cross-section communicating with the ends of said plurality of grooves. 4. A bearing structure according to claim 2 in which the grooves are of progressively decreasing cross-section.

5. A bearing structure according to claim 2 in which four grooves radiate from each feeding nozzle in an X-shaped pattern.

6. A hearing structure according to claim 1 in which one of the movable members is a shaft, the other movable member is a pillow block surrounding said shaft on only a portion of its periphery, and in which the pressure fluid feeding nozzles, the grooves and the outlet channels are formed in said pillow block.

7. A hearing structure according to claim 1 in which one of the movable members is subjected to an external force acting in a substantially constant radial direction, and which includes means for feeding pressure fluid directly to the inlet of at least one pressure zone located in a position to resist said external force, and means for feeding pressure fluid to the inlet of at least one other pressure zone from an outlet channel adjacent said first-named zone.

8. A bearing structure according to claim 1 in which one of the movable members is subjected to an external force acting in a substantially constant radial direction, and which includes means for feeding pressure fluid directly to the inlets of two pressure zones located in a position to References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,449,297 Hofier Sept. 14, 1948 2,459,826 Martellotti Jan. 25, 1949 2,495,516 Foster Jan. 24, 1950 2,578,711 Martellotti Dec. 18, 1951 FOREIGN PATENTS Number Country Date 454,557 Canada Feb. 15, 1949 553,673 Great Britain June 1, 1943 

